Ejector type refrigerating system



Oct. 4, 1938.. J. E. ROBE EJECTOR TYPE REFRIGERATING SYSTEM Original Filed June 6, 1954 Ivzvemtm wse zzzzzabb Patented oot. 4', 193$ UNITED- srA'ras nmcroa TYPE REFRIGERATING SYSTEM Joseph E. Robb, Kansas City, Kans, assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn, a corporation of Delaware Original application June 6, 1934, Serial No.

729,252. Divided and this application Novemher 20, 1935, Serial No. 50,688

16 Claims.

This invention relates to cooling or refrigerating systems, and more particularly to that type of system utilizing a steam jet ejector. This application is a division of copending application 5 Serial No. 729,252, filed on June 6, .1934.

An object of this invention is to provide a cooling system of the class described with safety devices and control devices whereby an eincient and safe operation of such a cooling system may be obtained.

It is an object of this invention to provide a control system for a.- cooling system having an evaporator, an ejector, a condenser and a boiler wherein the boiler is placed in operation in response'to a condition to be controlled and wherein the ejector is placed in operation in response 7 to boiler pressures.

It is another object of this invention to provide a control system for a cooling system of the type described above wherein the boiler is protected by means of a safety pilot control, a high limit control, a low-water cut-off control and a control device responsive -to the vacuum in the condenser.

It is another object ofthis invention to provide safety controls for a cooling system of the type outlined above wherein control devices responsive to evaporator temperatures are utilized to prevent operation of the ejector in case the evaporator temperature becomes too low or too high.

Still another object of this invention is to provide a refrigerating system of the type utilizing a condenser, an ejector, an'evaporator and a boiler with means for controlling the flow of cooling fluid to a point ofuse, means for controlling the flow of condensing water to the condenser, means for controlling the operation of the ejector and means for controlling the operation of the boiler wherein the boiler operating means is controlled 4,0 in response to a condition to be controlled and in response to the condition oi. the boilerand the vacuum in the condenser, wherein the ejector is controlled in response to boiler pressures and evaporator temperatures and wherein the means for controlling the flow of cooling fluid and condensing water is controlled in response to boiler pressure and evaporator temperatures.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing, in which drawing is diagrammatically illustrated the cooling or refrigerating system of my invention.

Referring now to the drawing','the evaporator is designated at "land is connected'by a'steam jet ejector H to a condenser i 2 in the manner known in the art. Steam is supplied to the ejector l i by means of a pipe l3 under the control of a valve M. The pipe I3 is connected into a steam header i5 leading from a boiler shown at Hi. The valve M controlling the supply of steam from the boiler It to the ejector H is controlled by means of a motor H, of a type well known in the art, which moves the valve M to either an extreme closed or an extreme open position. Condensed steam is drawn from the condenser I2 through a pipe l8 and is fed back to the boiler l 6 by means of a circulating and vacuum pump i9. The condenser coil diagrammatically illustrated at 20 in the condenser i2 is connected by pipes 2| and 22 to a cooling tower generally designated at ,23. The warm condensing water is drawn from the condenser l2 through the pipe 22 by the circulating pump 24 and is sprayed in the cooling tower 23 by means of a spray 25. A fan 26 for forcing relatively cool air in the cooling tower aids in the cooling of the condensing water. The cooled condensing water is returned from the tower 23 to the condenser coil 20 by the pipe 2|.

The evaporator l I] is connected by pipes 29 and 30 to a cooling coil 3| which may be located in a conditioning unit generally designated at 32. The cooling fluid is circulated through the evaporator Hl, the pipes 29 and 30 andthe cooling coil 3| by means of a circulating pump 33.

The operation of this type of cooling system is well known in the art and a detailed description thereof is not considered necessary, it being sufficient to state that upon opening of the valve l4 steam is admitted to the ejector H to'create a vacuum in the evaporator ill and by reason of this vacuum the cooling fluid leading from the cooling coil 3.| and sprayed into the evaporator I0 is cooled. and returned by the pipe 30 to the cooling coil 3|, wherebythe temperature within the conditioningunit 32 is lowered. The steam used in this cooling of the cooling fluid is condensed Within the condenser l2 and returned to the boiler l6.

For purposes of illustration, a gas burner 35 has been shown 'for firing the boiler l6. Gas is supplied to the gas burner 35 through a supply pipe 36 under the control of a gas valve 31 operated by a motor means 38. The motor means 38 is well known in the art and it is sufiicient to state that upon energization of the motor means 38 the valve -31 is opened, and upon deenergization thereof the valve 31 is closed. A pipe 39 leading from the gas supply pipe 36 ahead of the valve 31 connects to a pilot light 40, and responding to the pilot light 48 is a bimetallic element 4| which is adapted to engage a contact 42. When the pilot light 48 is lit, the bimetallic element 4| en-' gages the contact 42, and if the pilot light 48 should become extinguished the bimetallic element 4| disengages the contact 42.

For purposes of safe-guarding the operation of the boiler I6, this invention contemplates the use of a low-water cut-off mechanism generally designated at 43 and operating a switch 44, thearrangement being such that when the level of the boiler water is normal the switch 44 is in a. circuit-making position as shown in the drawing. This invention also contemplates the use of a high limit safety control mechanism generally designated at 45 and may comprise a bellows 46 connected by a pipe 41 to the steam header l5. The bellows 46 is adapted to operate a pivoted lever 48 which carries a mercury switch 49. The mercury switch 49 is provided with a plurality of contacts, the left-hand ones of which may be designated low pressure contacts, and the righthand ones may be designated high pressure contacts. The bellows 46 is actuated by the steam pressure within the header I5 and the arrangement is such that when the steam pressure is normal the left-hand or low pressure contacts are engaged by the mercury, and if the pressure within the boiler I6 should become excessive the mercury switch 49 is tilted so that the mercury engages the high pressure contacts. The high limit switch 45 may be adjusted so that it will be tilted to the position opposite that shown in the drawing when the boiler pressure exceeds, say, 16

pounds.

A vacuum switch is generally designated at 5| and may comprise a bellows 52 connected by a.

pipe 53 to the interior of the condenser I2. The bellows 52 operates a pivoted lever 54 which carries a mercury switch 55. The mercury switch 55 is therefore operated in response to vacuum existing within the condenser I2 and the mechanism 5| is preferably adjusted so that the mer f cury switch 55 is moved to a circuit-making position upon the occurrence of 26 inches of mercury vacuum in the condenser I2.

A pressure switch designated generally at 51 may comprise a bellows 58 which is connected by a pipe 59 to the pipe I3 ahead of the valve I4. The bellows 58 operates a pivoted lever 68 which carries a mercury switch 6|. cury switch 6| containsleft-hand low pressure contacts and right-hand high pressure contacts, the arrangement being such that when the pressure within the pipe I3 increases to 13 pounds the mercury switch is tilted to the position opposite that shown in the drawing to make contact between the high pressure contacts, and when the pressure within the pipe I3 drops to say pounds the mercury switch 6| is tilted to the position shown in the drawing to make contact between the low pressure contacts.

This invention also contemplates the use of temperature responsive switching mechanisms generally designated at 63 and 18. The temperature responsive switching mechanism 63 may comprise a bellows 64 connected by a capillary tube 65 to a bulb 66 which is located within the evaporator I8. The bellows 64 operates a pivoted lever 61 which carries a mercury switch 68 The temperature responsive switching mechanism I8 may comprise a bellows "II connected by a capillary tube 12 to a bulb I3 also located within the evaporator I8. The bellows H. operates a pivoted lever 14 which carries a mercury switch 15.

The mer- The mercury switch 68 of the temperature responsive device 63 contains a plurality ofcontacts, the arrangement/being such that when the temperature within the evaporator decreases to say 40, the mercury switch is tilted from the position shown in the drawing to a position wherein the left-hand contacts are made. The mercury switch 68 is normally in the position shown in the drawing. The mercury switch I5 of the temperature responsive device 18 also contains a plurality of contacts and the arrangement is such that when the temperature within the evaporator I8 increases to a predetermined high value, say 60, the mercury switch is tilted to make contact between the left-hand contacts thereof. The mercury switch 15 is normally maintained in the position shown in the drawmg.

A time switch is generally designated at 11 and may comprise a cam I8 which operates a pivoted lever I9, which in turn carries a mercury switch 88. The cam 'I8 may be operated by means of a rotor, not shown, and a' field winding 8| in the manner well known in the art. The arrangement is such that during day-time, the mercury switch is maintained in a circuit-making position, and during night periods when it is desired to have a shut-down of the cooling system the mercury switch may be moved to a circuitbreaking position.

A condition responsive device is generally designated at 83 and for purposes of illustration, this condition responsive device is shown to comprise a, bimetallic element 84 responding to changes in the temperatureto be controlled. The bimetallic element 84 operates a carrier 85 which carries a mercury switch '86, the arrangement being such that upon an increase in temperature asv affecting the bimetallic element 84, the carrier 85 is moved in the direction indicated by the character H to move the switch 86 to a making position.

A relay is generally designated at 88 and comprises a relay coil 89 for operating switch arms 98 and 9|. Upon energization of the relay coil 89 the switch arms 98 and 9I are moved into engagement with contacts 92 and 94, and upon deenergization of the relay coil 89, the switch arms 98 and 9| are moved out of engagement with the contacts 92 and 94 and the switch arm 98 is moved into engagement with the contact 93.

A relay generally designated at 95 comprises an energizing coil 96 and a bucking coil 91 for operating switch arms 98 and 99, the arrangement being such that when the energizing coil 96 is energized, switch arms 98 and 99 are moved into engagement with contacts I88 and IN, and when the energizing coil 96 is deenergized or when the energizing coil 96 and the bucking coil 91 are both energized the switch arms 98 and 99 are moved out of engagement with the contacts I88 and IN.

Another relay generally designated at I82 comprises a relay coil I83 which moves a switch arm I84 into engagement with a contact I85 upon energization thereof. This invention also contemplates the use of three more relays generally designated at I86, H8 and. H4, respectively, the

relay I86 comprising a relay coil I81 operating a switch arm I88 with respect to a contact I89, the relay ||8 comprising a relay coil III for operating a switch arm 2 with respect to a contact H3 and the relay II4 comprising a relay coil II5 for operating a, switch arm H6 with respect to a contact I".

circuit- I iii Line wires I20 and I'll leading from some source of power, not shown, are connected to a primary l22 of a step-down transformer M3, having a secondary I24. One end of the secondary M t is connected by a wire M to one of the electrodes of the mercury switch 336, and the other electrode thereof is connected by a wire 8% to one end of the relay coil 89. The other end of the relay coil 89 is connected by a wireit'l to the other end of the secondary i2 5. Upon an increase in temperature as affecting the bimetallic element M the mercury switch 86 is moved to a circuit-making position to complete a circuit from the secondary I24, through wire are, mercury switch 88, wire MB, relay coil lit and wire iti back to the secondary w ll. Energization of the relay coil 89 causes movement of the switch arms 90 and ill into engagement with the contacts 92 and M, respectively. Movement of the switch arm ti into engagement with the contact ii i completes a circuit from a line wire its, through wire ltll, mercury switch 8U, wire H32, contact M, switch arm 96, wire Q33, Wire 53 5, relay coil Hit of relay m2 and wires H35 and $136 back to the other line wire itil, providing the mercury switch all is maintained in a circuitmaking position as for day operation. Completion of this circuit causes energization of the relay coil N33 to move the switch arm tilt into engagement with the contact 8% to complete a circuit from a line wire ltd, through switch arm iil i, contact Hi5, wire B62, electrically operated vacuum pump id and line wire itl. Completion of this circuit causes operation of the vacuum pump it to draw condensate from the condenser l2 and to produce a vacuum therein.

When the vacuum within the condenser i?! so produced reaches, say 26 inches of mercury, the switch of the vacuum responsive device 58 is moved to a circuit-making position to complete a circuit from the line wire its, through wire till, mercury switch Ht, wire i552, contact as, switch arm ill, wires its and i377, mercury switch wire ltd, mercury switch M of the 'lowwater cut-off mechanism '33, wire its, primary hit of a step-down transformer Ml having a secondary M2, and wires llfi and iii; back to the line wire ltit. Completion of this circuit causes energization of the step-down transformer Ml. The transformer Mil will remain energized so long as the mercury switches 1%, lit, 55 and M are maintained in a circuit-making position. Therefore, if the temperature or condition to be controlled becomes satisfied, if night operation is desired, if the vacuum within the condenser it falls below 26 inches ofmercury, or if the liquid level within the boiler it should decrease to an abnormally low value the transformer Ml will become deenergized.

The motor 38 for operating the gas valve 3i is connected in parallel with the primary Mil of the step-down transformer Mi by wire i i i, contact ifll, switch arm 99 and wires M5 and its.

Therefore, when the switch arm 99 is moved into engagement with the contact Hill the motor 38 of the gas valve 3? will be energized to open the gas valve ill as long as the transformer Ml is supplied with power, the safety features protecting the operation of the transformer Ml also protecting the operation of the gas valve 317.

Movement of the switch arm so into engagement with the contact 92 in the manner pointed out above completes a circuit from one end of the secondary M2, through wire M8, contact 32, bimetallic element 4|, wire I49, wire 1150, contact 92, switch arm t0, wire i 52, low pressure contacts of the mercury switch is, wire I 53, energizing coil 96 of the relay 95, wire 05$ and wire E55 back to the secondary M2. Completion of this circuit causes movement of the switch arms 98 and $39 into engagement. with the contacts um and lili. Movement of the switch arm 99 into engagement with'the contact lfll causes opening of the gas valve t'l and consequent firing of the boiler it. Movement of the switch arm 96 into engagement with the contact lllfl completes a maintaining circuit through the energizing coil 96 from the secondary M2, through wire it, contact M, bimetallic element ill, wires Mil and 115i, switch arm Q8, contact mil, energizing coil 96 and wires l=5i and W5 back to the secondary M12. In this manner, the energizing coil at is maintained energized to maintain the valve 371 open as long as the step-down transformer Hill is energized in the manner pointed out above. If the boiler pressure should increase to an abnormally high value, to say 16 pounds, so as to move the mercury switch ill to a position opposite to that shown in the drawing, a circuit is completed from the secondary i 12, through wire M8, contact d2,

bimetallic element ill, wires Md and ibl, switch arm tit, contact mil, wire 553, high pressure contacts of mercury switch till, wires 65? and i 58, bucking coil W and wire E55 back to the secondary hi2. Completion of this circuit during the existence of abnormally high boiler temperature causes energization of the bucking 'coil Ql which counter-acts the action of the energizing coil :98 to allow the arms 98 and 99 to move out of engagement with the contacts mo and mu, re-

spectively. This breaks the circuit to the motor 38 of the gas valve 3'5 to stop firing of the boiler it until such time as the boiler pressure should decrease to a normal value. When the boiler pressure decreases to this normal value the mercury switch 219 is tilted to the position shown in the drawing to break the circuit through the bucking coil 96 to allow energizing coil Qt to move the switch arms 98 and as into engagement with the contacts Ito and till, thereby opening the gas valve 3i! to continue the operation of the boiler it.

If the bimetallic element M' becomes satisfied so as to move the mercury switch lit to the circuitbreaking position as shown in the drawing, the switch arm Elli is moved intolengagement with the contact 93 as the result of deenergization or the relay coil 89. Movement of the switch arm til into engagement with the contact 543 completes a circuit from the secondary 11512, through wire Gilli, contact 412, bimetallic element (ii, wires its and loll, switch arm at, contact Mid, wire H53, low pressure contacts of the mercury switch iii, wire 552, switch arm 9%, contact 93, wires Hit and 558, bucking coil ti and wire H55 back to the secondary Hi2. Completion of this circuit causes energization of the bucking coil ill! which counteracts the action of the energizing coil st to allow the switch arms 98 and 99 to move out of engagement with the contacts Mill and Hill, respectively. This causes deenergization of the motor 3% with consequent closing of the gas valve it'll thereby preventing the further operation of the boiler it.

In the manner pointed out above, the boiler it is under the direct control of the condition responsive device 83 and the vacuum existing within the condenser 02 so that when the temperature' afiecting the bimetallic element 84 is above the desired value, and when the vacuum iii;

within the condenser I2 is at the desired value, the boiler I 6 .is'placed in operation. Safety mechanisms are provided whereby operation of the boiler I6 is prevented in case the boiler pressure becomes abnormally high, or the pilot light' should be extinguished, or the boiler water levelshould become abnormally low.

common electrode thereof is connected by a wire I1| to the high temperature electrode of the mercury switch 68 of the temperatureresponsive device 63. The common electrode thereof is connected by a wire I12 to the high pressure contact of the mercury switch 6| of the pressure responsive device 51. The common electrode of mercury switch 6| is connected by a wire I13 to the motor I1. The motor I1 is'also connected by wires I14,. I15, I16, I11 and I18 to the left-.

electrodes of the mercury switches 6|, 68 and 15. respectively. a a

When the boiler has been placed in operation in the manner pointed out above, and when the boiler pressure has increased to a predetermined value, say 13 pounds, the mercury switch 6| is moved to a position opposite to that shown in the drawing, and since the mercury switches 68 and 15 are in their normal positions as shown in the drawing a circuit is completed from the secondary I61, through the wires I69, I13, high pressure electrodes of the mercury switch 6|, wire I12, mercury switch 68, wire |1|, mercury switch 15, wire I10, motor I1 and wire I68 back to the secondary Hi1. Completion of this circuit causes operation of the motor I1 to move the valve |4 to an open position to supply steam at 13 pounds pressure to the ejector II to cause operation of the steam jet refrigerating mechanism. If the evaporator temperature should decrease to such a value, say 40 F.,' wherein danger of freezing of the steam jet refrigerating mechanism would occur, the mercury switch 68 is tiltedto the position opposite to that shown in the drawing to break the above-referred to circuit and to complete a circuit from the secondary I61, through wires I69 and I13, mercury switch 6|, wire ,I12, mercury switch 68, wires I11, I16 and "4', motor I1 and wire I68 back to the secondary I61. Completion of this circuit causes closing of the valve I4 whereby the further supply of steam to the ejector II is prevented until such time as the evaporator temperature should increase above the predetermined low value of say 40. Iii this manner, freezing of the refrigerating system isprevented.

If for some reason or other the evaporator is riot cooled by the operation of the ejector and the evaporator temperature should rise to a value above say 60, the mercury switch 16 is tiltedto a position opposite that shown in the drawing to break the above opening circuit for the valve I4 and to complete a circuit from the secondary I61, throushwires I69 and I13, mercury switch 6|, wire I12, mercury switch 68, wire "I, mercury switch 15,wires I18, I16 and I14, motor I1 and wire I68 back to the secondary I81. Completion of this circuit also causes closing of the valve I4."

Therefore, it the steam jet refrigerating apparatus fails to function properly for some reason or other so as to allow the temperature or the evapi A 1 orator to rise above a predetermined high value of 60 the valve I4 is closed to prevent the further operation of the steam jet refrigerating apparatus.

When the boiler I6 is deenergized in the manner pointed out above by reason of the condition responsive device 83 being satisfied, the boiler pressure decreases, and when the boiler pressure decreases to a predetermined value of say 10 pounds, the mercury switch 6| of the pressure responsive device 51 is tilted to the position shown in the drawing to break the above-referred to circuit for opening the valve I4 and to complete a circuit from the secondary I61 through wires I69 and I13, mercury switch 6|, wires I15 and I14, motor I1 and wire I68 back to the secondary I61. Completion of this last mentioned circuit causes closing of the valve I4.

From the above it is seen that I have provided a means whereby the steam jet refrigerating mechanism is placed in operation when the boiler pressure rises to a predetermined value, and is placed out of operation when the boiler pressure decreases to a predetermined lower value, or when the evaporatortemperature; i. e. the temperature of the chilled water, decreases below a predeter- Inined value where freezing is liable to occur, or increases above a predetermined higher value which may be caused by faulty operation of the refrigerating mechanism. In this manner, safe operation of a steam jet refrigerating mechanism is assured.

The motor I1 operates a lever I64 which carries a mercury switch I19, the arrangement being such thatwhen the motor -.|1 is operated to move the valve I4 to an open position the mercury switch I19 is moved to a circuit-making position, and when the valve I4 is moved to a closed position by the motor H the mercury switch is moved to a circuit-breaking position. Movement of the valve I4 to an open position in the manner pointed out above completes a circuit from the line wire I29 through wire I80, mercury switch I19, wire |8| and through three branch circuits, the first being through relay coil I01 of the relay I06 and wire I82 back to the other line wire I30, the second being through wire I83, relay coil III of the relay H and wire I84 back to the other line wire I30, and the third being through wire I83, relay coil of the relay 4 and wire I85 back to the other line wire I 30. Therefore, when the mercury switch I19 is moved to a circuit making position the relay coils I01, III and H5 are energized.

Energization of the relay coil I01 causes movement of the switch arm I08 into engagement with the contact I09 to complete a circuit from I09, switch arm I08 and wire I89 back to the other line wire I30. the circulating pfimp 33 to circulate the chilled water through the cooling coil 3| located -.in the conditioning unit 32.

Energization of the relay coil III causes movement of the switch arm 2 into engagement with the contact 3- to complete a circuit from the line wire I28, throughwire I90, switch arm II2, contact-H3, wire I9I, electrically operated fan or blower 26 and wire I92 back to the other line wire I38. This causes operation of the fan or blower to increase the cooling action of the cooling tower 23.

Energization of the relay coil 5 moves the switch arm 6 into engagement with the con- This causes operation oi aieasaa be established more quickly upon a, demand for tact ill to complete a circuit from the line wire lit, through wire switch arm lit, contact ill, wire ill-l, electrically operated circulating pump 2t and wire 5% back to the other line wire 030. This causes operation of the pump M to convey warmcondensing water from the C011",

denser it to the cooling tower iii and to convey the cooled condensing water from the cooling tower 23 back to the condenser it.

Summarizing briefly the operation of my control system as applied to a steam jet or ejector type refrigerating system having an evaporator, a steam jet ejecton, a condenser and a boiler, it is seen that upon a call for cooling the vac- 'uum pump it associated with the condenser i2 is placed in operation to create a predetermined vacuum within the condenser. "When the vacuurn has reached a predetermined value, say 26 inches of mercury, the boiler it is placed in operation to produce steam to be supplied to the ejector ii. The operation of the boiler is safeguarded by means of a high limit controller it, a low-water cut-oft mechanism lift and a safety pilot arrangement dll. When the boiler has produced steam at 13 pounds pressure the valve id controlling the now o fsuch steam to the ejector ii is opened whereby the refrigerating niechanism is placed in operation. The refrigerating mechanism is safeguarded by the temperature hit responsive devices and lit to preventoperation of the refrigerating mechanism in case the evaporator temperature or chilled water temperature should decrease to a predetermined low value, or increase to a predetermined high value. Opening of the valve id in this manner likewise causes operation of the circulating pump for circulating the chilled water through the cooling coil ill of the air conditioning unit 32, causes operation of the circulating pump i'or circulating the condensing water through the condenser i2 and the cooling tower 23, causes operation of the blower or fan it: to increase the cooling action of the cooling tower When the condition to be controlled is restored to the desired value the firing oi the boiler it is prevented and the vacuum on the condenser it is broken. This allows a decrease in holler pressure and when the holler pressure has decreased to a predetermined amount of ii) pounds the valve id is closed and the refrigerating mechanism is placed out of operation and the circulation of the chilled water, theclrculation oi the condensing water and the operation of the blower or fan is stopped.

From a practical standpoint the steam jet ejector it cannot be operated unless there is a proper vacuum since steam cannot be generated in the boiler iii unless there is a proper vacuum. However, it may happen that the vacuum in the condenser i2 is less than the desired Flt inches of mercury, and at the same time there may be suflicient steam present in the boiler it to cause opening of the steam valve id. If it is desired to eliminate this remote possibility, the vacuum responsive switching mechanism at may be removed from in circuit with the primary no of the step-down transformer ldi and placed in circuit with the motor ii for operating the steam valve M, such a change requiring a double ended mercury switch rather than the single=ended mercury switch shown. This change in connections might have the further advantage of allowing the vacuum to be produced and steam pressure generated concurrently so that the proper vacuum and the proper steam pressure would cooling by the condition responsive device 83.

From the above it is seen that I have provided a novel control arrangement for use with a steam jet or ejector type refrigerating mechanism,

Iwherein'such a mechanism is efiiciently operajzed, and wherein safe-guards are provided whereby the refrigerating mechanism will be shut down in case of dangerous or faulty operation.

Although I have. disclosed one form of my invention, modifications thereof will become apparent to those'slsilled in the art and, consequently, this invention is to be limited only by the scope of the appended claims and the prior art. a

I claim as my -invention:

1. In a cooling system having a condenser, an ejector, an evaporator and a steam boiler, the

combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for firing the boiler to increase the boiler steam pressure,

-' and means responsive to a predetermined steam pressure for placing the ejector in operation.

2. in a cooling system having a condenser, an ejector, an evaporator and a steam boiler, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for fir ing the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation, and means responsive to a predetermined low evaporator temperature ior stopping operation of the ejector.

3. In a cooling system having a condenser, an ejector, an evaporator and a steam boiler, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the'production of a predetermined vacuum in the condenser for firing the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing ejector in operation, and means responsive to a predetermined high evaporator temperature ior stopping operation of the ejector.

ii. In a cooling system having a condenser, an ejector, an evaporator and a steam boiler, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenserfor firing the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation, and means responsive to predetermined high and low evaporator temperatures for stopping operation of the ejector.

5. In a cooling system having a condenser, an

' ejector, an evaporator, a steam boiler and a cooling device, the combination of means responsive cooling device, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser; means responsive to the production of a predetermined vacuum in the condenser for flring the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation and for circulating cooling fluid from the evaporator to the cooling device, and means responsive to evaporator temperature for stopping operation of the ejector and circulation of the cooling fluid.

7. In a cooling system having a condenser, an

ejector, an evaporator and a steam boiler, the

combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for flring the boiler to increase the boiler steam pressure, and means responsive to a predetermined steam. pressure for placing the ejector in operation and for supplying condensing fluid to the condenser.

8. In a cooling system having a condenser, an ejector, an evaporator and a steam boiler, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for firing the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation and for supplying-condensing fluid to the condenser, and means responsive to evaporator temperature for stopping operation of the ejector and the supply of condensing fluid to the condenser.

9. In a cooling system having a condenser, an ejector, an evaporator, a steam boiler and a cooling device, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for firing the boiler to increase the boiler steam pressure, and means responsive to a predetermined steam pressure for placing the ejector in operation, for circulating cooling fluid from the evaporator to the cooling device and for supplying condensing fluid to the condenser.

10. In a cooling system having a condenser, an ejector, an evaporator, a steam boiler and a cooling device, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production or a predetermined vacuum in the condenser for firing the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation, for circulating cooling fluid from the evaporator to the cooling device and for supplying condensing fluid to the condenser, and means responsive to evaporator temperature for stopping operation of the ejectoni'or stopping circulation of the cooling fluid and for stopping the supply of condensing fluid to the evaporator.

11. In a cooling systemhaving a condenser, an ejector, an evaporator and a steam boiler, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production of a predetermined vacuum in the condenser for flring the boiler to increase the boiler steam pressure, means responsive to a predetermined steam pressure for placing the ejector in operation, and time controlled means for rendering said means responsive to a demand for cooling inoperative.

12. A cooling system having a condenser, an evaporator and an ejector, the combination of means responsive to a demand for cooling for producing a vacuum in the condenser, and means responsive to the production or a vacuum in the condenser for placing the ejector in operation and for supplying condensing fluid to the condenser.

13. A cooling system having a condenser, an

evaporator and an ejector, the combination of means responsive to a demand for cooling tor producing a vacuum in the condenser, means re- .sponsive to the production of a vacuum in the the evaporator to the cooling device.

15. A cooling system having a condenser, an evaporator, an ejector and a cooling'device, the combination of means responsive to a demand for cooling for producing a vacuum inthe condenser, means responsive to the production or a vacuum in the condenser for placing the ejector in operation and for circulating cooling fluid from the evaporator to the cooling device, and means responsive to evaporator temperature for stopping operation of the ejector and circulation of the cooling fluid.

16., A cooling system having a condenser, an

evaporator and an ejector, the combinationo! means responsive to a demand for cooling for producing a vacuum in the condenser, means responsive to the production 01 a vacuum in the condenser for placing the ejector in operation, and time controlled means for rendering said means responsive to a demand for cooling inoperative at predetermined times.

JOSEPH E. none. 

